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Louisiana
7
Science
iLEAP
TM
TABLE OF CONTENTS
Introduction ....................................................................................................................... 1
Tips for Taking Science Tests ......................................................................... 1
Unit 1 – The Nature of Science ................................................................................... 3
Review 1: Thinking Like a Scientist ............................................................. 4
Benchmarks/GLEs: SI-M-A1/3; SI-M-A4/10; SI-M-A5/14–16;
SI-M-A6/17, 18; SI-M-A7/21; SI-M-A8/23, 24; SI-M-B1/25–27;
SI-M-B2/28; SI-M-B4/33; SI-M-B5/34–37
Review 2: Planning and Conducting an Experiment.......................... 18
Benchmarks/GLEs: SI-M-A1/1, 2; SI-M-A2/4, 5; SI-M-A3/6–8;
SI-M-A4/11–13; SI-M-A7/20, 22; SI-M-B2/28; SI-M-B3/31; SI-M-B5/36
Review 3: Communicating and Understanding Data ........................ 38
Benchmarks/GLEs: SI-M-A3/8, 9; SI-M-A4/11; SI-M-A7/19; SI-M-B3/32
Review 4: Science, Technology, and Society.......................................... 59
Benchmarks/GLEs: SI-M-B3/29, 30; SI-M-B6/38; SI-M-B7/39, 40
Unit 2 – Properties of Matter .................................................................................... 69
Review 5: Physical Properties of Matter .................................................. 70
Benchmarks/GLEs: PS-M-A1; PS-M-A4; PS-M-A5
Review 6: Chemical Properties of Matter................................................ 79
Benchmarks/GLEs: PS-M-A1; PS-M-A2; PS-M-A3; PS-M-A6;
PS-M-A7; PS-M-A8; PS-M-A9/1
Unit 3 – Life Sciences .................................................................................................... 91
Review 7: Cell Structure and Function..................................................... 92
Benchmarks/GLEs: LS-M-A1/2, 3; LS-M-A2/4; LS-M-A4/7, 8; LS-M-B1/15
Review 8: Human Health ........................................................................... 109
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Review 9: Reproduction and Heredity.................................................. 127
Benchmarks/GLEs: LS-M-B1/14, 15; LS-M-B2/16–18; LS-M-B3/19–22
Review 10: Adaptations for Survival ...................................................... 143
Duplicating any part of this book is prohibited by law.
Benchmarks/GLEs: LS-M-D1/30, 31; LS-M-D2/32–34
Review 11: Life Cycles of Plants and Animals ..................................... 164
Benchmarks/GLEs: LS-M-A3/5, 6
Unit 4 – Environmental Science ........................................................................... 177
Review 12: Ecosystems ............................................................................... 178
Benchmarks/GLEs: LS-M-C1/23; LS-M-C2/24; LS-M-C3/25, 26;
LS-M-C4/27–29; SE-M-A1/36; SE-M-A2/37, 38; SE-M-A5/40
Review 13: Protecting Ecosystems and the Environment ............. 199
Benchmarks/GLEs: SE-M-A1/35, 36; SE-M-A2/37, 38;
SE-M-A3; SE-M-A4/39; SE-M-A6; SE-M-A7/41, 42;
SE-M-A8/43; SE-M-A9; SE-M-A10
iii
Table of Contents
Appendix......................................................................................................................... 217
Glossary ........................................................................................................... 219
Word Links ...................................................................................................... 229
Benchmark and GLE codes are listed for each
review in the table of contents and for each
page in the shaded gray bars that run across
the tops of the pages in the workbook (see
example to the right). These codes indicate
which Benchmarks and GLEs are covered in a
given review or on a given page.
Unit 3
Standards: A1, B2, C3
100
iv
Duplicating any part of this book is prohibited by law.
To the Teacher:
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7 /13
Review 8
Human Health
Your body is complex; it is made up of many different parts and systems.
Some of these systems you can control. For example, you can choose
whether to eat a piece of bread or a candy bar. However, many of your
body’s systems are self-controlled. Whatever you choose to eat, once the
food gets into your mouth, your body starts taking over, as though it
were on autopilot. Your tongue makes saliva to break down some of the
food. Muscles in your throat push the food down to your stomach. Your
brain tells your stomach to make acid that turns the food to slush. Your
intestines soak up nutrients from that slush, the nutrients your body
needs to keep working. Your blood, pushed and pulled along by your
heart, carries these nutrients all around your body. Any wastes from the
body and anything left over is handled by your kidneys, your liver, and
your colon.
You cannot control most of these processes. They are automatic. It’s a
good thing your body does all these things by itself. If you had to think
about doing all this stuff, you’d be making thousands of little choices
every minute of every day just to stay alive. You wouldn’t have time to
talk to friends, listen to music, read a book, or go have fun on a Friday
night. You couldn’t even sleep, because your mind would have to stay
awake to tell your body how!
Above: Your body is
complex and made
up of many different
parts and systems.
Duplicating any part of this book is prohibited by law.
This review is all about the systems that keep your body running without you even thinking
about them—all the systems that leave you free to think about things like school.
Words
Words
to Know
to
Know
alveoli
antibiotics
antimicrobial
agents
artery
blood
bone
capillary
cartilage
diaphragm
esophagus
excretory system
heart
homeostasis
infectious
diseases
intestine
joint
lungs
noninfectious
diseases
organ
organ systems
parasite
pathogen
plasma
puberty
red blood cells
stomach
tissues
trachea
vein
vertebrates
villi
white blood cells
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Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9,10; LS-M-A6/11,12; LS-M-A7/13
Word Links
Look at the “Words to Know” list on the previous page. Circle two words that you don’t
know or that you want to learn more about. Then, on a separate piece of paper, write
each word and what you think each word means.
Tissues, Organs, and Organ Systems
The descriptions in this review focus on the human body. However, much of this description
also applies to many vertebrates—animals with backbones. Vertebrates include fish,
amphibians, reptiles, birds, and mammals.
The most basic complete structures in the body are cells. Cells that do the same job work
together to form body tissues. Each tissue is made of a specific type of cell that has a
particular function. For example, muscles are tissues. Muscles are made of muscle cells. Their
job is to contract and relax, making the body move. Groups of tissues, sometimes with
specialized functions, make up organs. Organs have specific functions in the body that are
usually unique, like the liver. Sometimes organs come in pairs, like the lungs and kidneys.
Organs, in turn, work together in organ systems. These are groups of organs that accomplish
some goal. For instance, the heart, the blood, and the blood vessels work together to form the
circulatory system, the body’s transit system. Each function that humans and most other
animals must do to stay alive (breathing, eating, thinking, etc.) is made possible by groups of
specialized cells arranged into tissues, organs, and organ systems.
What is the difference between an organelle and an organ?
Now let’s look at some of the organ systems at work within the human body.
110
Duplicating any part of this book is prohibited by law.
Place the following in order from least complex to most complex: organ, organ system,
organelle, tissue, cell, vertebrate.
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
The Skeletal System
The skeletal system is made up of the different bones of the body. Bones vary tremendously
in their size and shape, depending on their function. For example, the bones in your legs are
long, straight, and circular. Your ribs, on the other hand, are curved and flat. The skeletal
system has many functions. For example, some bones protect organs. The bones in your skull
protect your brain; the bones of your rib cage protect your heart and lungs.
The skeletal system is also important because it provides support for the body.
Explain what this means.
The skeletal system helps your body move. To see how this is,
bend your arm at the elbow. This movement is possible
because the bones of your arm, like all bones in your body, are
connected by joints. Many joints in the skeletal system are
lined with cartilage. Cartilage is a soft, flexible, smooth tissue.
It lets the joints slide past each other easily. It also cushions
and protects the ends of bones during movement.
The skeletal system contains many joints. Identify two
joints other than your knee joint.
Joint 1:
Joint 2:
Duplicating any part of this book is prohibited by law.
What kinds of movements do the joints you identified
produce?
Knee Joint
femur
joint
cartilage
tibia
Above: Cartilage allows
the joints to slide past
each other and cushions
and protects the ends of
bones during movement.
Arthritis is a condition in which the cartilage in a joint has worn away. What happens to a
joint that is no longer cushioned and covered by cartilage?
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Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
The Circulatory System
The circulatory system consists of the heart, blood, and blood vessels. This system is the
body’s delivery service. It provides all tissues in the body with oxygen and nutrients. It is also
the trash collection system because it removes waste products, such as carbon dioxide.
Blood
The heart acts as a pump that keeps blood moving through blood vessels. Blood is a thick
liquid that transports nutrients and wastes. Blood is made of three main components.
r Plasma: Over half of your blood is made of plasma, which is mostly water.
r Red blood cells: These blood cells transport oxygen throughout the body.
r White blood cells: These blood cells help fight infections.
Vessels
Vessels transport blood throughout the body. There are three types of blood vessels.
r Arteries carry blood away from the heart.
r Veins carry blood toward the heart.
r Capillaries are tiny vessels that join arteries and veins and reach all cells of the body.
Capillaries can be thinner than a single strand of hair.
Blood travels to the lungs, where red blood cells pick up oxygen. The red blood cells carry this
oxygen to other parts of the body. Blood also travels to the digestive system, where nutrients
from food are absorbed into the bloodstream and distributed to other tissues.
artery
to lungs
vein
from lungs
artery
vein
KEY
= Oxygen-rich blood
capillaries
112
= Oxygen-poor blood
Duplicating any part of this book is prohibited by law.
Human Circulatory System
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Willy claims that arteries carry oxygenated blood and veins carry blood with carbon
dioxide. Is this correct? Explain your answer.
When you exercise, your heart beats much faster than when you sit still. Explain why
physical activity causes this to happen.
Duplicating any part of this book is prohibited by law.
Which blood vessels, arteries, veins, or capillaries, contain blood at the highest pressure?
Explain your answer.
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Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
The Respiratory System
The respiratory system works closely with the circulatory system to provide the body’s tissues
with oxygen and to remove carbon dioxide from the body. The respiratory system controls
respiration, or breathing. You may remember respiration from a previous review. The same
word is used for breathing and for the process of breaking down sugars, because animals
breathe in order to exchange the gases used in cellular respiration.
When you inhale, a thin muscle called the diaphragm contracts. When this happens, your
lungs, which are like big sacks or sponges, expand to hold air. When the diaphragm relaxes, it
helps squeeze the air back out of your lungs. Air enters mostly through the nose. The nose is
full of tiny hairs that filter dust from the air. Air then travels to the trachea, a hollow tube that
carries air to the lungs. Once in the lungs, the air travels to tiny air sacs called alveoli. Oxygen
diffuses over membranes in the alveoli, entering the blood. Red blood cells grab on to the
oxygen and take it away in the bloodstream. At the same time, carbon dioxide diffuses into
the lungs. When you exhale, the carbon dioxide–rich air travels back up the trachea and out
through the nose or mouth.
Human Respiratory System
nose
alveolus
trachea
capillary
diaphragm
Look at the diagram above. What do the arrows going between the alveolus and the
capillary represent?
At high elevations, like in the mountains, less oxygen is in the air than at sea level. If you
traveled to the mountains, what effect would it have on your respiration? Explain how
this relates to diffusion.
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lungs
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
The Digestive System
The digestive system provides your body with the nutrients you need to survive. These
nutrients come from the food you eat. The process of breaking down food begins in the
mouth. When you chew, your teeth break down food physically. Your saliva begins breaking it
down chemically. The food is then swallowed and travels through the esophagus, a long tube
that connects the mouth to the stomach. Once in the stomach, food is broken down even
more by stomach acid. The food then travels from the stomach to the intestine. The intestine
is a long, snakelike tube coiled just below your stomach. In fact, when stretched end-to-end,
an adult intestine is over 7 meters long! The intestine is divided into two parts, the small
intestine and the large intestine. Nutrients from food are absorbed into the blood in the small
intestine. Anything that is not absorbed is carried to the large intestine. The large intestine
removes water from leftover food and stores the waste until it is expelled from the body.
Human Digestive System
mouth
esophagus
stomach
large intestine
small intestine
Duplicating any part of this book is prohibited by law.
In what ways are the digestive system and the respiratory system similar to each other?
Why do you think the small intestine needs to be so long?
115
Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Organ Systems Working Together
Organ systems do not function alone. All the systems are needed to make a functioning human
body. Several groups of systems work closely together to maintain balance within the body.
The heart, blood, and blood vessels make the circulatory system. The nose, mouth, trachea,
and lungs make the respiratory system. What is the relationship between the two systems? To
get energy from food nutrients, all cells need a constant supply of oxygen. The process that
releases this energy also makes carbon dioxide, which is toxic to humans. Our bodies must
constantly breathe in new oxygen and breathe out carbon dioxide. (This relationship with
breathing is why the process of breaking down food energy is known as respiration.) The
circulatory and respiratory systems work together to exchange gases with the outside
environment and distribute them throughout the body.
Organ systems often work in larger groups. The circulatory system, as the conveyor belt of the
body, is responsible for moving nutrients to cells, too. In order to do this, it works closely with
the digestive system to pick up nutrients from the villi in the small intestine and bring them
to the cells. At the same time, this cycle would not be complete without the oxygen from the
respiratory system and also a fourth system, the excretory system. This system is responsible
for removing cellular wastes and excess water from the body. This system, too, relies on the
circulatory system for transportation and relies on the digestive system for the nutrients to
power itself. Ultimately, every system in the body depends on all the others. They must all
function together, or the body as a whole will not work properly.
List two more examples of body systems that work together. Explain how they need
each other to do their own jobs properly.
People do not go through metamorphosis, like insects. However, we
still experience tremendous change as we grow and develop.
Infancy and Childhood
Humans’ most distinctive feature is our intelligence. Our brains are so
large that we are born before they finish developing. As a result,
human newborns are completely helpless. They cannot walk, crawl, or
communicate. However, over the first few months and years, humans
develop dramatically. By six to ten months, they are usually crawling.
They say their first words at around one year old and speak in
complete sentences by age three. Throughout childhood, children’s
brains have one major task: learning.
116
Above: Over the first
few months and years,
humans grow and
develop dramatically.
Duplicating any part of this book is prohibited by law.
Growth and Development of Humans
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Puberty
The puberty phase begins around ages 8 to 14.
Pubescent people experience growth spurts, where
their overall physical size increases very rapidly. As
puberty continues and the child becomes a teenager,
many other changes occur. Pubescent people begin to
experience sexual attraction to others. They often
experience very strong emotions, without the life
experience to control those emotions. Puberty can
be a difficult time. However, it does end, usually by the
early twenties.
Describe two major changes between childhood
and puberty.
Above: Puberty begins around ages
8 to 14, a time when many emotional
and physical changes occur.
As people age, their basic abilities (like memory and physical strength) tend to decline.
What advantages make up for these changes? Explain.
Duplicating any part of this book is prohibited by law.
Adulthood and Old Age
Adult humans experience a gradual decline as they move
toward old age. Although their thinking often becomes
more sophisticated due to increased life experience, their
basic abilities, both physical and mental, slowly decrease.
As we age, we lose muscle mass and sometimes find it
more difficult to remember things or pay attention. We
also begin to develop soreness and aches. We may
develop age-related symptoms, such as hearing loss,
vision loss, or arthritis. Many of these problems can be
moderated through mental or physical exercise. By
constantly using the basic faculties, we can help slow or
reverse age-related decline. Diseases become more and
more common as we age.
Above: Many of the problems
associated with aging can be
moderated through mental or
physical exercise.
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Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Influences on Human Health
Everyone gets sick sometimes. No one remains young and healthy forever. However, some
people are healthier than others. There are many influences on human health. Although many
of these are out of our hands, we can control others. It is important to make good decisions in
order to stay healthy.
Genetic Factors
Some people are predisposed to illness. Some people have family histories of diseases, such
as heart disease, depression, or cancer. Genetic factors make some people gain more weight
than others. Sometimes entire groups of people are more prone to certain illnesses. For
example, African Americans are more likely to have high blood pressure, so doctors advise
that they eat less sodium. Genes can even cause specific diseases.
Maintenance
Our decisions greatly impact how healthy we are and how good we feel. Many little decisions
will help us lead healthier lives. For example, washing our hands regularly, especially after
using the restroom and before preparing food and eating, will help prevent germs that cause
colds. Brushing and flossing will help avoid painful dental problems.
Toxins
We can make important choices about what we put into our bodies. Many chemical
substances can cause diseases, like cancer or heart disease. Nicotine and other substances in
cigarettes cause cancer, strokes, and heart disease. Excessive alcohol consumption can cause
damage to the heart, liver, and brain. Illegal drugs can have dangerous effects, including
addiction, hallucinations, psychosis, and sudden death, in addition to many of the threats
associated with cigarettes.
Many people choose to use these toxic substances. As with diet and exercise, people who
make good choices lead happier, healthier, longer lives.
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Two of the most important choices to protect our health are our choices about nutrition and
exercise. Good nutrition helps prevent diseases of all kinds and helps to control weight.
Nutrition advice changes frequently. However, the constants seem to be that we should eat a
balanced diet with many green and leafy vegetables, limit the amount of meat we eat, and
get protein from beans and dairy products. In general, most Americans eat too much and
exercise too little. Exercise is wonderful for the body. Studies have shown that exercise helps
us prevent many kinds of illness and stay both strong and flexible as we age. Exercise even
helps preserve good brain function. People who exercise more are less forgetful, more
focused, and less likely to suffer depression and age-related mental decline. Perhaps most
important of all, people who exercise regularly tend to feel better than people who do not.
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
How are genetic factors different from the other influences mentioned here?
Choose two decision that people can make to improve their health. Describe the
advantages of each choice.
Disease
Everyone gets sick sometimes. Disease is a disruption of the natural body balance, or
homeostasis. Diseased body systems fail to work properly or at all. Some diseases cause the
heart or kidneys to stop working. Others may cause serious tissue swelling, muscle weakness,
or severe confusion. Many things can cause disease. However, public health professionals talk
about two main kinds of disease: infectious and noninfectious.
Duplicating any part of this book is prohibited by law.
Infectious diseases can be spread from one person to another. They are caused by pathogens.
A pathogen is an organism or virus that causes disease in another organism. Common
pathogens include bacteria, viruses, fungi, and protists. Parasites are a special kind of pathogen.
They are multicellular. All pathogens find homes inside the host body and begin multiplying,
sickening the hosts. Different diseases are caused by different pathogens. For example, the
common cold, mumps, and warts are caused by different viruses. Athlete’s foot is a fungal
infection. Sinus infections and strep throat, however, are usually caused by different bacteria.
Thousands of pathogens can infect and damage the health of organisms. Many can be very
severe. Diseases, such as human immunodeficiency virus (HIV) or the Ebola virus cause lifethreatening diseases. Bacteria can cause lung infections, stomach flu, and other problems.
Fungi often attack the skin and respiratory system. For example, gardeners are often exposed
to a fungus named Histoplasma capsulatum. This fungus, common in chicken droppings used
as gardening manure, can cause coughing, lung congestion, fever, chills, etc. Parasites can
also cause gruesome and deadly infections. For example, tapeworms reside in the digestive
system and other parasites enter the heart, lungs, and liver.
How Infectious Disease Spreads
Diseases that spread from one organism (the carrier) to another are contagious. Some
diseases are more contagious than others. Some spread only through direct physical contact.
Others spread by sharing objects, by sharing food or drink, or even through the air.
119
Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
For example, imagine borrowing a pen from someone who has a cold. If some of the virus is
on the person’s pen, you may get it on your hands when you hold the pen. If you then wipe
your nose with your hands, you may catch the cold.
Why does washing your hands reduce your risk of catching a cold?
Pathogens may also be spread through vectors, which are animals that carry the disease. The
vector may or may not show symptoms of the disease. For example, the West Nile virus is
often fatal to birds, but it is carried by mosquitoes that suffer no symptoms. The mosquitoes
are a vector that spreads the virus from bird to bird (or from bird to human).
Fighting Disease-Causing Pathogens
A growing problem with antibiotic use is antibiotic resistance. Suppose a person is given an
antibiotic to treat a bacterial infection. The antibiotic will kill most of the bacteria, but a few
bacteria may have a genetic trait that lets them survive. These survivors multiply or share their
genes with other bacteria. As a result, populations of bacteria begin to have various levels of
resistance to the antibiotic. An “arms race” develops, as doctors need larger doses of existing
antibiotics, combinations of antibiotics, or even more powerful new drugs to combat the
resistant bacteria. Meanwhile, the bacteria may become resistant to new antibiotics as well,
leading to potentially uncontrollable infectious diseases.
A doctor tells a patient to take an antibiotic for six days. After three days, the patient feels
better and stops taking the antibiotic. Give two reasons why the person should take the
antibiotic for the full six days.
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How do science and technology fight the spread of disease caused by pathogens?
Antimicrobial agents are chemicals that stop microbe (single-celled organism) growth or
destroy microbes. Common antimicrobial agents produced by technology include bleach,
hydrogen peroxide, and iodine. Antimicrobial agents produced by microorganisms are called
antibiotics. For example, the mold Penicillium notatum makes a chemical that can kill several
types of bacteria. Scientists isolated this chemical in the 1930s, producing the first antibiotic
treatment for disease, penicillin. Today, many other antibiotics are available. They stop
bacteria in different ways. Some antibiotics keep bacteria from producing their proteins;
others damage bacteria cell membranes. Antibiotics do not attack the cells of multicellular
organisms, and they do not affect viruses.
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Noninfectious diseases cannot be passed from one person to another, but they can still
cause great harm. Some noninfectious diseases are genetic. People are either born with them
or have a high chance of developing them. The disease called cystic fibrosis is a genetic
disease. Other noninfectious diseases come from mutations inside the body. Cancer, for
instance, is caused by mutations in cells. The mutations allow the cells to divide very fast and
stop cooperating with the tissue they live in. Cancerous cells form large masses called tumors.
Individual tumor cells, or clumps of cells, can break away and spread through the bloodstream
to other parts of the body. These cells then grow into new tumors at their new sites. Due to
genetics, some people have an increased risk of developing some types of cancers.
Why would the daughter of a woman with breast cancer want to have regular exams to
check for cancer?
Other kinds of noninfectious disease are called lifestyle diseases. These come from
maltreating the body. Smoking cigarettes is a prime example. Smoking increases the risk of a
person developing lung cancer. Much of the cure for this and other lifestyle diseases involves
changing personal habits—and changing societies so that healthy personal choices are easier
to make.
What social changes might make it easier for people to avoid cigarette smoke?
Duplicating any part of this book is prohibited by law.
Mistreatment of the body does not always come from lifestyle choices. Exposure to toxic
chemicals, like lead and mercury, can seriously disrupt many life processes and even kill.
We continuously monitor the environment for these causes of disease.
Finally, the causes of some diseases are still largely mysteries to us. We do not know, for
instance, what causes asthma, a lung disease that makes breathing difficult. It may be caused
by genetic factors, or it may be caused by infection or environmental factors. Perhaps it is
caused by all three. We do not understand the causes of many mental illnesses. Medicine has
made great strides in the last hundred years. As a result, we live twice as long as we used to.
However, there is still a great deal we wish to learn about diseases and health.
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Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Word Links
Now that you’ve read through this review, go back to the words you circled in the
“Words to Know” list. Write each word in the “Word Links” table at the back of this
workbook. Fill out one row for each word.
Keys to Keep
Humans are made of many organ systems, which are made of organs.
Organs are made of tissues, which are collections of cells.
Like animals, people grow and develop over time.
Human health requires people to be careful and make good choices.
Diseases are caused by many factors but mainly by invasive
microorganisms.
Have you ever heard of the dance called the Peabody? Luckily for Candace Pert, she
had. She was at a party when a man asked if anyone knew how to do that dance.
Because Pert and her husband knew the Peabody, they joined the man on the dance
floor. Afterward, the three began talking. Pert mentioned that she wanted to study the
chemicals of the human brain to learn more about how they make the brain work.
She lived close to a university in Maryland where a man named Dr. Sol Snyder was
studying these things. Pert wanted to earn her Ph.D. working
with him, but the university had rejected her application. The
man at the party happened to be a good friend of Snyder, and
he promised to talk to the brain researcher. Pert wrote a letter
telling about all her scientific goals, and, a short time later,
Snyder called to tell Pert that she had been accepted to the
university. Pert now has become a famous scientist and has
made some important discoveries about how the brain works.
She is also an author, a mother, and a pretty good dancer.
Candace B. Pert
(United States 1946–)
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People in Science
Review 8: Human Health
Benchmarks/GLEs: LS-M-A5/9, 10; LS-M-A6/11, 12; LS-M-A7/13
Explore It Yourself
The following simulation will give you a better sense of how microbes spread. The year is
1350, and your classroom is a town in plague-ridden Europe. Your town has not been struck
with the dreaded disease, but three seemingly healthy merchants have just arrived. They
bring news of the plague, and everyone is eager to hear it. (At this time in human history,
nobody knew about microbes or how contagious diseases spread.)
Your teacher has three piles of paper squares. Each pile is a different color, and each color
represents a different type of microbe.
Step 1: Your teacher chooses three students to be the merchants new to town. Each
merchant comes to the front and picks up one pile of paper.
Step 2: Each merchant picks two townspeople to hear news of the plague. Those
townspeople come up front to greet the merchant that chose them.
Step 3: Each merchant keeps one square and gives five squares to each townsperson he or
she picked.
Step 4: The townspeople with five squares now choose two more townspeople with whom
to share the news. These new townspeople come up to hear the news from the
person that chose them.
Step 5: Each townsperson with five squares keeps one square and gives two squares to each
person he or she picked.
Step 6: Each townsperson with two squares chooses one person who hasn’t yet heard the
news and gives that person a square.
Duplicating any part of this book is prohibited by law.
Step 7: By now, all of the squares should be distributed. Any leftover squares should be
placed onto the teacher’s desk.
Step 8: Everyone returns to their homes (their seats).
Step 9: Record the number of people holding each color of square:
Purple:
Green:
Blue:
Step 10: Your teacher reveals the identity of each colored square and the effects of having
that type of bacterium or virus.
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Unit 3 – Life Sciences
Benchmarks/GLEs: LS-M-A5/9-10; LS-M-A6/11-12; LS-M-A7/13
1.
Explain how the plague in this simulation was spread.
2.
Why were some people able to avoid getting the plague?
3.
All the people in this town became infected with either a type of bacterium or a virus.
Why did some people live and others die?
4.
Today, we know that rats carry the bacteria that cause the plague. Fleas bite both rats
and people. Use your knowledge of vectors to explain how fleas helped to spread
the plague.
5.
Scientific understanding and technological treatment of contagious disease have
advanced since 1350. Describe two advancements in how humans understand and treat
contagious diseases.
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Louisiana iLEAP Science Practice begins on the following page.
Duplicating any part of this book is prohibited by law.
What Does It Mean?
Review 8: Louisiana i LEAP Science Practice
i LEAP Science Practice
1.
2.
Duplicating any part of this book is prohibited by law.
3.
4.
Where does chemical digestion first begin?
A.
in the stomach
B.
in the mouth
C.
in the esophagus
D.
in the large intestine
When humans breathe, oxygen travels through the respiratory system into the
bloodstream. Where does this occur?
A.
in the diaphragm
B.
in the nose
C.
in the trachea
D.
in the lungs
Which statement best describes capillaries?
A.
Capillaries are larger than arteries.
B.
Capillaries carry blood back to the heart.
C.
Capillaries are smaller than arteries.
D.
Capillaries carry only white blood cells.
Which of these helps to slow the effects of aging?
A.
exercising regularly
B.
avoiding all alcohol
C.
drinking lots of water
D.
brushing teeth regularly
Louisiana i LEAP Science Practice
125
Review 8: Louisiana i LEAP Science Practice
5.
6.
What is the most effective way to
prevent the most common
diseases?
A.
avoiding risky sexual behaviors
B.
taking antibiotics when feeling ill
C.
getting enough exercise
regularly
D.
frequently washing your hands
Examine the image below.
X
7.
Cancer and rheumatoid arthritis are
two diseases in which the body’s
normal functions stop working.
Cancerous cells reproduce
uncontrollably, which damages the
body’s function and often causes
death. In rheumatoid arthritis, the
body’s immune system attacks the
cartilage, which normally protects
joints. This causes pain, bone loss,
and loss of mobility.
A.
Compare these two diseases.
How are they similar? Consider
factors, such as severity,
length of disease, and whether
or not they are contagious.
B.
Name three diseases that are
different from cancer and
rheumatoid arthritis. Describe
how these diseases are
different. Consider the same
factors you mentioned in the
previous question.
W
Z
Which structure in the figure helps
cushion bones during movement?
126
A.
W
B.
X
C.
Y
D.
Z
Louisiana i LEAP Science Practice
Duplicating any part of this book is prohibited by law.
Y